Multiple-perspective imaging has been used for reconstructing a 3D model of an object. Some examples of achieving multiple-perspective imaging include:                (i) setting up as many cameras as the number of multiple-perspective images required;        (ii) using two cameras to capture a pair of two-dimensional (2D) images from different perspectives, and relying on a software algorithm to determine the intermediate perspectives by interpolation, so that respective points of the 3D model are determined based on corresponding epipolar lines in the images captured by the two cameras. In other words, the image planes of the images are manipulated; and        (iii) relying on cameras with built-in depth keys which provide depth information in each pixel of the captured images for reconstructing the 3D model.        
Methods (i) and (iii) relies on sophisticated hardware. The advantage of method (i) is that the large amount of data captured makes it possible to obtain any perspective view which the user may require. However, the large number of cameras needed for method (i) means that it is technically and economically impracticable to set up and maintain such a system. Furthermore, the system is inefficient since large amounts of the captured data are redundant. This is because adjacent pairs of the cameras capture almost identical images of portions of the object near the zero-plane of the cameras in Cartesian space.
By contrast, method (ii) relies on sophisticated software instead of hardware. Although method (ii) only requires a pair of cameras and thus offers a more viable option than method (i) in respect of technicality and cost, the accuracy of the intermediate perspectives is typically compromised by factors like disorder (due to a feature of the object being seen by one camera and not the other), incorrect matching, and lack of information due to occlusion (there may be portions of the object which are not visible to either camera). Of the three methods above, this is least able to guarantee perfect images, and perfect interpolation is practically impossible in any circumstances. As for method (iii), the resolution and accuracy of the depth information provided in each pixel of the images captured using the depth cameras are inconsistent, and method (iii) too is susceptible to problems such as occlusion.
The present invention aims to provide a 3D-imaging apparatus and a method of forming a 3D image of an object, which at least ameliorate the problems described above, and also to provide the general public with both an alternative 3D-imaging apparatus and an alternative method of forming a 3D imaging of an object.